When Stephen Wheeler realized he had an aching, swollen finger, he called his primary care doctor, who works for MedStar Health. The doctor referred him to PromptCare, an urgent care clinic in a strip mall in the Baltimore suburbs.

Wheeler says he probably would have ended up waiting a long time if he'd gone to the doctor. And even longer at the emergency room.

But they are all about speedy service here at the urgent care center; Wheeler got in and out in 15 minutes. There's a timer outside of every exam room so the staff knows how long a patient has been waiting. Because Wheeler was already in the system, the clinic was able to pull up his electronic health records and find out if he was allergic to any medications or was due for any other care.

Hospitals already own more than a quarter of the nearly 9,000 urgent care clinics in the U.S. that are drawing patients away from emergency rooms.

"We're still in the very early stages of this trend," says Tom Charland, who runs a consulting company called Merchant Medicine that focuses on walk-in clinics.

He cautions that it's still unclear whether hospitals will actually be successful at managing urgent care centers. Hospitals tend to be good at providing high-quality care, but they're not always so good at customer service.

"Things like understanding how to locate an urgent care clinic in the right retail complex, keeping the wait times down, offering people to book their appointments online — hospitals have yet to prove that they can do that effectively," he says.

But Bob Gilbert, who is in charge of ambulatory services for MedStar, says he's proud of PromptCare's location. He says his company is ready.

"Here we are in a local shopping center where you'd normally not find health care," he says. "People are used to coming here, they know where it is, the parking is free."

The hospital makes money for every patient the clinic refers to a MedStar facility for follow-up care, like a CT scan or an appointment with an orthopedist. Patients who don't yet have a regular source of health care can be referred to a MedStar primary care doctor. But Gilbert says the clinics are also a long-term investment.

And the future is this: Insurers and Medicare are starting to pay providers to keep patients healthy. Providers get a bonus if they manage to lower the cost of the medical services their patients need. These clinics could be a key part of this strategy for hospitals.

The Baltimore location is the first of seven urgent care clinics Gilbert is opening over the next year; MedStar is hoping for 15 in the next few years.

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